SIP SIMPLE Client SDK

= MSRP API =

[[TOC(WikiStart, Sip*, depth=3)]]

Message Session Relay Protocol (MSRP) is a protocol for transmitting a series of related instant messages in the context of a session. Message sessions are treated like any other media stream when set up via a rendezvous or session creation protocol such as the Session Initiation Protocol (SIP). 

 * MSRP sessions are defined in [http://tools.ietf.org/html/rfc4975 RFC 4975].

 * MSRP relay extension used for NAT traversal of instant messaging and file transfer sessions is defined in [http://tools.ietf.org/html/rfc4976 RFC 4976].

The MSRP protocol is implemented by [http://devel.ag-projects.com/cgi-bin/darcsweb.cgi?r=python-msrplib;a=summary msrplib] Python package. On top of it, {{{sipsimple}}} provides higher level classes integrated into middleware notification and configuration systems:

 * {{{sipsimple.msrp.MSRPChat}}}

 * {{{sipsimple.msrp.MSRPFileTransfer}}}

 * {{{sipsimple.msrp.MSRPDesktopSharing}}}

Those classes are used internally by [wiki:SipMiddlewareApi#Session Session], which provides the necessary methods to access their features. The notifications posted by these classes are also handled internally by [wiki:SipMiddlewareApi#Session Session]. The notifications that are relevant to the user are then reposted by the Session instance.

Refer to [wiki:SipMiddlewareApi#Session Session documentation] for details on Session API.

== MSRPChat ==

{{{sipsimple.msrp.MSRPChat}}} implements Instance Messaging over MSRP in the context of SIPSIMPLE middleware. This class

 * automatically wraps outgoing messages with Message/CPIM if that's necessary according to accept-types

 * unwraps incoming Message/CPIM messages

 * plays notification sounds on received/sent message

=== methods ===

 '''!__init!__'''(''self'', ''account'', ''remote_uri'', ''outgoing'')::

 Initialize MSRPChat instance.

 '''initialize'''(''self'')::

 Initialize the MSRP connection; connect to the relay if necessary. When done, fire MSRPChatDidInitialize (with 'sdpmedia' attribute, containing the appropriate 'SDPMedia' instance)

 '''start'''(''self'', ''remote_media'')::

 Complete the MSRP connection establishment; this includes binding the MSRP session. [[BR]]

 When done, fire MSRPChatDidStart. At this point each incoming message is posted as a {{{MSRPChatGotMessage}}} notification

 '''end'''(''self'')::

 Close the MSRP connection or cleanup after initialize(), whatever is necessary. [[BR]]

 Before doing anything post {{{MSRPChatWillEnd}}}.

 When done, post {{{MSRPChatDidEnd}}}. If there was an error, post {{{MSRPChatDidFail}}}.

 {{{MSRPChatDidEnd}}} will be posted anyway.

=== notifications ===

 '''MSRPChatGotMessage''':

 Posted for each incoming message with the following attributes:

 - cpim_headers (dict); if cpim wrapper was not used, empty dict

 - message (MSRPData)

 - content (str) - the actual string that the remote user has typed

== MSRPFileTransfer ==

== MSRPDesktopSharing ==

== msrplib ==

{{{msrplib}}} is based upon [http://twistedmatrix.com twisted] and [http://devel.ag-projects.com/~denis/eventlet/ eventlet] and provides a set of

classes for establishing and managing MSRP connection.

The library consist of the following modules:

 '''msrplib.transport'''::

 Defines {{{MSRPTransport}}} class, which provides low level control over MSRP connection.

 '''msrplib.connect'''::

 Defines means to establish a connection, bind it, and provide an initialized {{{MSRPTransport}}} instance.

 '''msrplib.session'''::

 Defines {{{MSRPSession}}} class, which provides high level control over a MSRP connection.

 '''msrplib.protocol'''::

 Provides representation and parsing of MSRP entities - chunks and URIs.

 '''msrplib.trafficlog'''::

 Defines {{{Logger}}} class that is used through out the library to log the connection state.

=== Usage ===

==== Establish a connection ====

{{{msrplib.connect}}} provides a number of classes to establish a connection, so the first

thing to do is to select which one applies to your situation:

    1. Calling endpoint, not using a relay ({{{ConnectorDirect}}})

    2. Answering endpoint, not using a relay ({{{AcceptorDirect}}})

    3. Calling endpoint, using a relay ({{{ConnectorRelay}}})

    4. Answering endpoint, using a relay ({{{AcceptorRelay}}})

The answering endpoint may skip using the relay if sure that it's accessible

directly. The calling endpoint is unlikely to need the relay.

Once you have an instance of the right class (use the convenience functions

{{{get_connector()}}} and {{{get_acceptor()}}} to get one), the procedure to establish the

connection is the same:

{{{

full_local_path = connector.prepare()

try:

    ... put full_local_path in SDP 'a:path' attribute

    ... get full_remote_path from remote's 'a:path: attribute

    ... (the order of the above steps is reversed if you're the

    ... answering party, but that does not affect connector's usage)

    msrptransport = connector.complete(full_remote_path)

finally:

    connector.cleanup()

}}}

To customize connection's parameters, create a new {{{protocol.URI}}} object and pass

it to prepare() function, e.g.

{{{

local_uri = protocol.URI(use_tls=False, port=5000)

connector.prepare(local_uri)

}}}

{{{prepare()}}} may update {{{local_uri}}} in place with the actual connection parameters

used (e.g. if you specified port=0). 'port' attribute of {{{local_uri}}} is currently

only respected by {{{AcceptorDirect}}}.

Note that, acceptors and connectors are one-use only. Which means, that {{{AcceptorDirect}}}

will open a port just to handle one incoming connection and close it right after.

If your application behaves more like a server, i.e. opens a port and listens on it

constantly, use {{{MSRPServer}}} class.

=== Components ===

==== a connector or acceptor ====

===== attributes =====

===== methods =====

==== transport.MSRPTransport ====

Low level access to MSRP connection.

===== attributes =====

===== methods =====

 '''make_chunk'''(''self'', ''transaction_id''={{{None}}}, ''method''={{{'SEND'}}}, ''code''={{{None}}}, ''comment''={{{None}}}, ''data''={{{''}}}, ''contflag''={{{None}}}, ''start''={{{1}}}, ''end''={{{None}}}, ''length''={{{None}}}, ''message_id''={{{None}}})::

 Make a new chunk ({{{protocol.MSRPData}}} instance) with proper {{{From-Path}}}, {{{To-Path}}}, {{{Byte-Range}}} and {{{Message-ID}}} headers set up based on MSRPTransport's state and the parameters provided. Use ''data'' for payload, and ''start''/''end''/''length'' to generate {{{Byte-Range}}} header. Generate new random strings for default values of ''transaction_id'' and ''message_id''. 

 [[BR]]''contflag'':[[BR]]

 MSRP chunk's continuation flag ({{{'$'}}}, {{{'+'}}} or {{{'#'}}}). Default is {{{'$'}}}, unless you have a partial {{{SEND}}} chunk, in which case it is {{{'+'}}}

==== session.MSRPSession ====

===== attributes =====

===== methods =====

==== connect.MSRPServer ====

===== attributes =====

===== methods =====